Trailer running gear



Dec. 22, 1964 H. J. wooLsLAYER ETAL 3,162,464

TRAILER RUNNING GEAR 5 Sheets-Sheet l Filed Feb. 5, 1962 H .W\ l IANA l- 1 /|.|.|I |l|| l i M.\ H Hmmllllllm/ .Illmlwuhlw lllllllllllll Il, w Q N\ A. i. n 1 4 N\ Q .T llllllllll {T Lllll l 1 Q .Q v\\ LL nlp Q El n Dec. 22, 1964 H. J. wooLsLAYr-:R ETAL 3,162,464

TRAILER RUNNING GEAR 5 Sheets-Sheet 2 Filed Feb. 5, 1962 ,4 TTOR/VEVS Dec. 22, 1964 H. J. wooLsLAYx-:R ETAL 3,162,464

TRAILER RUNNING GEAR 5 Sheets-Sheet 3 Filed Feb. 5, 1962 HSM..

INVENTORS HOME/Q J. WOOLSLAYER CEC/L JENK/NS CHARLES D. IDU/N65 mwwm Dec. 22, 1964 H. J. wooLsLAYER ETAL 3,162,464

TRAILER RUNNING GEAR Filed Feb. 5, 1962 5 Sheets-Sheet 4 ii?, INVENTORS 1,1 CHARLES o. 1D0/N65 Dec. 22, 1964 H. J. wooLsLAYr-:R ETAL 3,162,454

TRAILER RUNNING GEAR 5 Sheets-Sheet 5 Filed Feb. 5, 1962 INVENTORS MEQ WOLSZA YEQ A TTOR/YEKS United States Patent tlice 3,162,464 Patented Dec. 22, 1954 3,162,464 TRAILER RUNNING GEAR Homer J. Woolslayer, Cecil .Ienliinsg and Charles D.

Iddings, Tulsa, Okla., assigner-s to Lee C. Moore Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Feb. 5, 1962, Ser. No. 170,984 2 Claims. (Cl. 23d-104.5)

This invention relates to running gear for the rear ends of trailers, and more particularly to running gear in which there is at least one short axle at each side of the trailer, with a wheel on each end of the axle.

lt is common practice to provide the rear ends of heavy trailers with at least two axially aligned wheels at each side of the trailer. Each pair of wheels are mounted on the opposite ends of a short axle, the central portion of which is rigidly connected to an axle housing rotatable around a trunnion that extends lengthwise of the trailer. If tandem axles are used, the trunnions are at the opposite ends of a walking beam pivotally connected to the trailer frame on a transverse axis. As the trailer travels over a road or lield the axles can rock back and forth on their trunnions as one wheel or another passes over a rise or through a depression. This rocking or tilting of the axles permits the load to be distributed substantially uniformly on all of the tires. However, when the trailer is turned, the load is greatly increased on one time on each axle as that tire scuts against the ground. At the same time, the axle may be tilted so much that the other tire carried by it will rub against the frame. These things Wear the tires unduly. If the turn is quite sharp and the load great, there is even danger that the attening and scuiing sideways of a tire may cause it to come oli the wheel.

It is among the objects of this invention to provide a trailer running gear, in which tree rotation of the axles around their trunnions is prevented, in which tilting of the axles on their trunnions is controlled, in which there is more equal loading ot the tires on curves than heretofore, in which scuing of the tires against the ground and trailer -trame is reduced, and in which all of these things are accomplished in a relatively simple manner.

In accordance with this invention an axle housing is ,rotatably mounted on the trunnion of a rigid member that extends lengthwise of an overlying trailer trarne, to which it is connected. An axle is secured to the housing and extends across it. The opposite ends of the axle are formed to receive wheels equipped with tires. Connected with the axlie housing and its supporting member are controlled yielding means for continually resisting turning of the housing on the trunnion in either direction from a predetermined normal position. The yielding means may be springs, or a torsion member extending lengthwise of the trunnion, or both. When a walking beam is used, it may be tubular with an axle housing on each end of it and a torsion bar extending through it and rigidly connected to both housings.

The invention is illustrated in the accompanying drawings, in which FIG. l is a plan view of our running gear at one side of the back of a trailer, with the tires shown in dotted lines;

FIG. 2 is a side View of the running gear, shown partly in vertical section;

FIG. 3 is a cross section taken on the line III-III of FIG. 1;

FIG. 4 is a combination end view and cross section taken on the line IV--IV of FIG. l;

FIG. 5 is a fragmentary side View of a modification, shown partly in section;

FIG. 6 is a View similar to FIG. 5 of another embodiment of the invention;

FIG. 7 is a fragmentary perspective view of the central` portion of the torsion member shown in FIG. 6;

FIGS. 8 and 9 are side and plan views, respectively, of a further embodiment of the invention;

FIG. l0 is an enlarged fragmentary side View, partly broken away in section; and

FIG. 11 is an end view of the running gear taken on the line XI-XI of FIG. 10.r

Referring to FIGS. l to 4 of the drawings, a supporting member W, which is itself rigid', extends lengthwise of the overlying trailer frame F, to which the member is connected near one side of the rear end. A similar member (not shown) supports the opposite side of the frame. The rigid member illustrated is a walking beam formed from a rigid tube 1 that is reinforced by a pair of 11p- Wardly extending parallel plates 2 welded to its opposite sides. The side plates are tapered upwardly and are covered by a top plate 3 welded to them. AExtending through the centers of the two side plates is horizontal tubular member 4, in the outer ends of which are mounted bearings 5 that receive a cross shaft 6 projecting outwardly beyond them. Rigidly mounted on the ends of this shaft is a yoke 7 that straddles the upper part of the walking beam and that is secured to the bottom of a bolster 8 projecting down from the bottom of the trailer frame.

The ends of the side plates 2 and their connecting top plate 3 are spaced a short distance from the adjacent ends of the tube 1, and each of those projecting ends of the tube is encircled by a flange 10 welded to it. The space between that flange and the adjacent end of the tube forms a trunnion, on which an axle housing H is rotatably mounted; Each housing has a sleeve-like body 11 encircling the tube, a pair of laterally spaced plates 12 that project upward in parallel planes extending lengthwise of the tube, and a tubular member 13 rigidly mounted in openings in the plates. The housings are held on the trunnions by flange rings 14 and ring nuts 15 screwed onto the tube ends. Rigidly mounted on each tubular member 13 is a short axle 16 that projects from its opposite ends for receiving a pair of rubber tired wheels. For the sake of clearness, the brakes are not shown. The walking beam allows equalization of load on the front and rear tires, which are disposed in tandem.

With the construction described thus far, which is more or less conventional, the axles would be free to rotate any amount around the walking beam. As explained above, heretofore unrestrained rocking of the axles Would permit the tires to scui excessively While the trailer was going around a corner, it would produce severe unequal deflection of the tires, and it would also create the danger of some of the tires being pulled olf the wheels on sharp turns. It is a feature of this invention that these shortcommgs are avoided by adding means to the running gear to yieldingly control and restrain turning of the axle housings on the walking beam without eliminating all rocking of the axles.

One way of doing this, as shown in FIGS. 2 and 4, is to connect springs between the axle housings and the walking beam. Thus, the bottom of each axle housing may be provided with a downwardly extending radial lug 20, and the tube at the opposite side of ange 19 be provided with a pair of spaced lugs 21 that extend downward and then outward along opposite sides of the housing lug, from which they normally are spaced several inches. Mounted in the two outside lugs is a rod 22 that extends through an enlarged opening 23 in the center lug. Coil springs 24 encircle this rod at opposite sides of the center lug and are compressed between it and the ouside lugs to center the lug 20 between the other two. It will be axle horizontal, parallel to the trailer frame, but if sufi Y 3 v iieient force is applied to tilt the axle or if the trailer frame" tilts laterally relative to the axle, the housing lug 20will'be'swun'g toward one or the other of the tube lugs 21. However, such relative .motion of the lugs will be strsmslyresisted, ,and thereby .centralise by 011e. 01 the other of the coil springs. This will keep lthe load more. evenly distributed'on the tires at the opposite ends of the' axle, which is the ultimate purpose of this invention. That will reduce scufling and overloading ot' the' tires, land eliminate Aany aWhesL' 'i 'In so e cases where it may be felt that the coil springs may not be suicient to control the axles tothe extent desired, they can be assisted by artorsion member extendin'g through the walking beam tube and rigidly connected to fboth axle housings. Such an arrangement is shown ifi FIG. k5, where ythel torsion member is a solid high strengthsteel bar 26 thathas suiicient resilience to per-, inity it tobe twisted on itsfaxis to some extent'and to then spring fback" whenr the twisting Vforce is removed.

danger of yatireV being pulled from VhereverV a"torsion member isreferred to herein it is 'presumedrto'be suiiciently resilient furthe desired limited twisting. ,1 Y. y

In FIG. the Walking beam 27, the axle housings 28, the inner and outer lugs 29 and SG, the rods 3 1 and the coil springs 3 2 may all be the same'as those described for the first embodiment TofAk thisl invention, except that outer flanges Yon the'beam have been omitted. Around each retaining nut 33a bolting ,ring -3.4 is Welded to the ad'ioining axle housingQand a ange plate 3S is bolted to the 'outer face of thisV ring. ,The ange plate has a central openingY axially aligned withthe tube, and an outward-ly'projecting socket 36.." `The inside ofV the socket converges vawayfrom the tube and snugly receives the tapered endofv the torsion bar, which projects beyond the socket and has a threadedfend on which a retaining nut 37' is screwed. The bar and inside of the two sockets are provided with'key ways containing keys 38 torrigidrly connect the bar and sockets together.l i l y With thisconstruction, in orderlfor one axle to tilt relative to the other one, it Vnot only'must compress one of the coil springs 32, but it alsornust twist the torsion bar 2 6, whereby the tilting axle must overcome great resistance in order to rock on the walking beam. VIt'will be seen-that .tilting of vone axle inV one direction resists rocking of the other axle in the oppositedirection. Since in turning the trailer the front axle on` the beam tilts in a direction opposite to the rear axle, the Dtorsion b-ar can be relied onto create practically allof the resistance to such tilting if desired, in which case' the coil springs between the lugs canVV be relatively weak and used principally for. preventing unrestrained rot-ation of both axleY housf ings ,in the same direction. Infact, in case one is concerned only with controlling and limiting'rocking of the tandem axles in opposite'directions relative to each other, Ialldnot with limiting their tilting'in the same direction together, the coil springs and lugs oulld be omitted and only the torsion bar used. i Y

An embodiment of. the invention which may be pre-V ferred to those shown in FIGS. l to jfbecfause the exf posed yielding means are eliminated and placed inside the walking beam, is shown in FIGS. 6 and7.V In this running gear the walking beam 40 is made in substantially the same way asin FIG. 2 and is pivotally connected to a trailer frame bolster 41 through a yoke 42. Rotatably mounted Von 4the trunnions formed by the opposite ends of the walking beam tube 43 and axle housings 44 like those previously described, which contain short tandem axlee 45. Welded tothe outer end of each housing is a boltxng ring kd6, to which a flange plate #i7A is secured. The flange plate is provided with an outwardly projectying tapered socket 48, in which one tapered endof a torsion bar is rigidly mounted by means of a key 50 and a retaining nut 51.

This arrangement issubstantally the same as shown in FIG. 5, but instead of coil springs for resisting turning of the torsion bar, a torsion sleeve 53 is mounted inside the walking bearnlvr VThis sleeve may have substantially the same resistance to twisting as the bar. It encircles the bar and extends from one end ofthe Walking beam tube inwardly to about the center of' the bar.' The sleeve is spaced from the tubeand bar by an external ring 54 on f the outer end ofl the sleeve, and an internal ring 55 in the inner end of the sleeve. T he external ring is welded to both sleeve and tube, while Vthe internal ring is welded to the sleeve Iand theenlarged central portion of the torsion bar. To increasethe length of the latter weld, lthe sleeve and ring may be notched circumferentiallyas shown. l

The bar d@ and sleeve 53 together form a torsion member. If oneaxle tilts in one Vdirection from `its normal positionand the other axle tilts an equal amount in the opposite direction, the torsion bar will be twisted but the sleeve will not be aiected because thel center of the bar will notfturn. '.However, if one axle tilts more than the other, then the sleeve likewisewill be twisted and will help the torsion bar resist the tilting of the axles; The sleeve also restrains rotation of the torsion bar in the walking beam both axles attempt torock in the same direction, suchras when the trailer is travelling aiong a road with a high crown. if desired, the sleeve can be made in the form of a coilV spring encircling -the torsion bar in the same way. This embodiment of the invention also has the advantage that all'of the yielding means for continually resisting turning of the axle housings on the walking beam are concealedV and protected by the Vwalking beam. l,

The modiiication shown in the last four iigures of the V drawings is for use when tandem wheels are not employed. In this case they support for the single axle housing 60 at each side of the trailer is a relatively shorthorizontal tube 61 extending lengthwise of the trailer. A channel Y 62 may be welded to the top of the tube for the double Vhousing and has opposite ends :fory receiving rubber tired wheels; As in FIGS. vSand 6, a bolting ring 66 is welded to the outerv end of the'h'ousing so that a flange plate 67 can be attached toit. The taperedsocket 68 projecting from the ange plate receives the tapered outer end: of a torsion bar 69 held rigidly in the socket by a key 7i) and a nut 71 on the end of the bar. This bar may be only about half as long as the'ones previously described, but its effective length rand ilexibility are increased by a torsion sleeve '72 encircling the bar within the tube. YThe outer end of the sleeve is welded to the tube through an exterior spacing ring 73 whileithe inner end ofthe sleeve is welded to a spacing ring 74 'welded to the enlarged inner end of the torsion bar. The torsion member formed bythe sleeve and bar is completely yconcealed yand 'protected by the tube. It strongly resistsrocking of the axleon the tube, and thereforeithis construction VVhas the same advantages as the others described herein.

By` using running gear such'as'dislosped herein, tire '.Wear and the possibility. of accidentsresulting from serious adapted to extend lengthwise of an overlying trailer frame and including a longitudinal rigid tube and means midway between the ends thereof for pivotally connecting it to such a frame on a transevrse axis, an axle housing encircling each end of the tube and rotatably mounted thereon, an axle secured to each housing and extending across the tube, the opposite ends of each axle being formed to receive Wheels, a torsion member rotatably disposed in said tube and projecting from its ends, and means rigidly connecting the ends of said member with the adjoining axle housings whereby longitudinal tilting of either axle relative to the other one will be resisted by the resistance of the torsion member to twisting.

2. A trailer running gear comprising a walking beam adapted to extend lengthwise of an overlying trailer frame and including a longitudinal rigid tube and means midway between the ends thereof for pivotally connecting it to such a frame on a transverse axis, an axle housing encircling each end of the tube and rotatably mounted thereon, an axle secured to each housing and extending across the tube, the opposite ends of each axle being formed to receive Wheels, a torsion bar rotatably disposed in said tube and projecting from its ends, a cylindrical torsion member in the tube encircling said bar and extending from one end ot' the tube inwardly to the central part of the bar, means rigidly connecting the outer end of said member to the tube, means rigidly iconnecting the inner end of said member to the bar, and means rigidly connecting the ends of the bar With the adjoining axle housings.

References Cited in the iile of this patent UNITED STATES PATENTS 2,12l,862 Dodge June 28, 1938 2,238,002 Pointer Apr, 8, 1941 2,919,928 Hoter Tan. 5, 1960 FOREIGN PATENTS 321,257 Italy Sept. 28, 1934 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent Noa 1)g l2464 December 22Q 1964 Homer J., Woolslayer et al It is herebgr certified that error appears in the above numbered pat-` ent requiring correction and that the said Letters Patent should read as corrected below.

Signed and sealed this 27th day of April 1965o (SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A TRAILER RUNNING GEAR COMPRISING A WALKING BEAM ADAPTED TO EXTEND LENGTHWISE OF AN OVERLYING TRAILER FRAME AND INCLUDING A LONGITUDINAL RIGID TUBE AND MEANS MIDWAY BETWEEN THE ENDS THEREOF FOR PIVOTALLY CONNECTING IT TO SUCH A FRAME ON A TRANSEVERSE AXIS, AN AXLE HOUSING ENCIRCLING EACH END OF THE TUBE AND ROTATABLY MOUNTED THEREON, AN AXLE SECURED TO EACH HOUSING AND EXTENDING ACROSS THE TUBE, THE OPPOSITE ENDS OF EACH AXLE BEING FORMED TO RECEIVE WHEELS, A TORSION MEMBER ROTATABLY DISPOSED IN SAID TUBE AND PROJECTING FROM ITS ENDS, AND MEANS RIGIDLY CONNECTING THE ENDS OF SAID MEMBER WITH 